/*
 * Copyright (c) 2006-2007 Erin Catto http://www.gphysics.com
 *
 * This software is provided 'as-is', without any express or implied
 * warranty.  In no event will the authors be held liable for any damages
 * arising from the use of this software.
 * Permission is granted to anyone to use this software for any purpose,
 * including commercial applications, and to alter it and redistribute it
 * freely, subject to the following restrictions:
 * 1. The origin of this software must not be misrepresented; you must not
 * claim that you wrote the original software. If you use this software
 * in a product, an acknowledgment in the product documentation would be
 * appreciated but is not required.
 * 2. Altered source versions must be plainly marked as such, and must not be
 * misrepresented as being the original software.
 * 3. This notice may not be removed or altered from any source distribution.
 */

package org.box2dflash.dynamics {
	import org.box2dflash.collision.shapes.*;
	import org.box2dflash.dynamics.*;
	import org.box2dflash.common.*;
	use namespace Internal;

	/// Implement this class to provide collision filtering. In other words, you can implement
	/// this class if you want finer control over contact creation.
	
	public class ContactFilter {
		/// Return true if contact calculations should be performed between these two shapes.
		/// @warning for performance reasons this is only called when the AABBs begin to overlap.
		public  function shouldCollide(shape1:Shape, shape2:Shape):Boolean {
			var filter1:FilterData = shape1.filterData;
			var filter2:FilterData = shape2.filterData;
		
			if (filter1.groupIndex == filter2.groupIndex && filter1.groupIndex != 0) {
				return filter1.groupIndex > 0;
			}
		
			var collide:Boolean = (filter1.maskBits & filter2.categoryBits) != 0 && (filter1.categoryBits & filter2.maskBits) != 0;
			return collide;
		}

		static public var _defaultFilter:ContactFilter = new ContactFilter();
	}
}
